Electric circuit closing device operated by yarn tension



1966 s. DAVIES ETAL 3,227,833

ELECTRIC CIRCUIT CLOSING DEVICE OPERATED BY YARN TENSION Filed Aug. 20,1962 2 Sheets-Sheet 1 Inventors Sfdn/cy Davies Gw 717C001 78/1 Mar/vs 5yW V Attorneys Jan. 4, 1966 s. DAVIES ETAL 3,227,833

Filed Aug. 20, 1962 2 Sheets-Sheet 2 /0/ m [06 f 2/: /04 /05 /08 /07 m9A Home ys United States Patent 3,227,833 ELECTRIC CIRCUIT CLQSXNG DEVICEUFERATED BY YARN TENSKUN Stanley Davies, Newport, and Gwynfryn JohnMorris, Cwmbran, England, assignors to British Nylon pin= ners Limited,Pontypool, England Filed Aug. 20, 1962, Ser. No. 217,798 Claimspriority, application Great Britain, Aug. 25, 1961, 30,638/61 8 Claims.(Ci. 20tl6l.13)

This invention relates to an improved device for actuating a stopmotion, particularly suitable for use with textile warping or beamingmachines, which operates when excessively high or low tensions obtain inthe threadline. For some textile operations, for example warp knitting,it is sometimes desirable that yarns or threads be available on a formof package which allows a multiplicity of ends to be taken offsimultaneously and in parallel. In order to obtain yarns on such apackage the requisite number of bobbins are mounted on a support, forexample on a creel, and the yarns are fed through guides and reeds toform a fiat sheet which is wound upon a beam. This operation is commonlyknown as warping or beaming.

It occasionally happens during warping or beaming that the tension in athreadline increases to the point when the thread breaks, the breakusually occurring at the front reed of the machine where the threadlinetension reaches a maximum. This increase in tension may result fromfaulty supply packages, containers, caps, reeds or other damagedsurfaces with which the yarn comes into contact, the faulty surfaceusually being at or near to the creel. Threadline breaks also appearowing to creel run-outs, i.e. all of the yarn on a package is usedbefore the operative attending to the machine changes the package for afull one.

It is necessary when a threadline-break occurs to stop the machine sothat an operator can join the two broken ends of the thread togetherusually by knotting. Since it is not possible for the human eye toreadily detect threadline breaks in a wrap sheet which may contain manyhundreds of threads, devices designed to actuate stop motions areemployed which cause the machine to be stopped rapidly after athreadline break has occurred. The devices in current use are commonlyof the dropperarm or tow tension type in which weighted arms aresupported by the running threadline and when a break occurs in thethreadline the weighted arm falls and makes connection with anelectrical contact to close a circuit which operates a means forstopping the machine. Devices of this type, which are usually fitted ator near the creel, are not wholly effective in detecting threadlinebreaks which occur at or near the front reed, since a broken thread maybecome entangled with adjacent threadlines with the result that thetension in the yarn is maintained and therefore the dropper arm does notoperate and the brake passes undetected. The dropper arms of thesedevices require good frictionless bearings for efiicient operation andcontamination often prevents them from operating, thus allowing breaksto pass undetected. Another important defect of this type of deviceconcerns the delay which takes place on a break occurring and the stopmotion device operating to bring the machine to a stop. As a result ofthis delay a considerable quantity of yarn may be wound on to the beamafter a break occurs. In order to recover the broken end from the beamthe excess yarn may be wound back off the beam on to an accumulator.However the accumulator has only a limited capacity, e.g. in the regionof about 10 yards, and at high warping speeds too much yarn may be woundon to the beam for the broken end to be recovered;

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this end then becomes known as a lost end. The corresponding end fromthe creel has then to be marked, usually by tinting with a dye so thatit can be recognised during knitting, and banded in by wrapping aroundthe beam. Experience shows that about 10% of the threadline breaks whichoccur give rise to lost ends.

The elimination of lost ends is of great importance in the textile tradesince they are detrimental to beam quailty; each lost end resulting intwo stoppages during knitting thereby causing a loss in production andin addition the dye used in tinting may cause staining if it is notcompletely fugitive.

There is, therefore, a need for a device to actuate a stop motion whichwill operate either at the front reed of the warping machine, in whichcase the braking by the stop motion would have to be almostinstantaneous to prevent the broken end being wound on to the beam, orwhen conditions prevail which are likely to cause a threadline break.

It is known that, although the threadline break normally occurs at thefront reed of the warping machine where the threadline tension is at amaximum, it is usually the result of an increase in tension at the creelowing to faulty supply packages, caps, containers or the like. Thereforeif gross increases in tension of the threadline at the creel aredetected and made to operate a means for stopping the machine, then themachine operator is able to take remedial action to relieve the tensionand prevent a break occurring.

The object of the present invention is, therefore, to provide a devicefor actuating a stop motion to halt the feeding of threads to a beam,which operates the said stop motion when the tension in a threadlinebecomes either excessivley high, owing to the occurrence of a fault atthe creel for example, or falls to nearly zero following a threadlinebreak, and which thus largely overcomes the objections of the prior artdevices.

Accordingly the present invention provides a device for actuating a stopmotion connected with a thread feeding or winding mechanism comprising apivotally mounted beam adapted to be moved into electrical contact witha contact bar when the tension of a thread falls below a predeterminedlimit and a second beam also adapted to be moved into electrical contactwith a contact bar when the tension of a thread rises above apredetermined limit, characterised in that a member having athreadengaging portion is both connected with said first mentioned beamnormally to hold it out of electrical contact with said contact bar andcarries means for moving said second mentioned beam into electricalcontact with said contact bar, said second mentioned beam beingsupported by a fixed member and carrying an adjustable weight whichnormally holds it out of contact with said contact bar.

A preferred embodiment of the invention, hereinafter more fullydescribed, comprises a combination of a chain and lightweight beams, oneof which beams is arranged to be supported by a thread. Upon an increasein tension in the threadline to a predetermined value the beams areraised and make a connection with a contact bar which closes an electriccircuit operating a relay which in turn actuates a means for stoppingthe machine. The threadline tension at which the beam closes theelectric circuit is determined by the weight of the chain which issuspended by one end from one of the beams. The other end of the chainis attached to a sprocket mounted on a shaft one end of which terminatesin a pointer knob. By turning the knob, and hence also the shaft andsprocket, the amount of chain suspended from the beam can be varied. Theshaft on which the sprocket is mounted is designed to carry a pluralityof such sprockets so that an equivalent number of stop motion devicescan be simultaneously adjusted by turning the one knob, for examplethirty such stop motion devices can be mounted so as to be adjustable bythe knob.

Should the tension in the threadline increase so rapidly that a breakoccurs before the machine can be brought to a complete halt, therecovery of the broken end from the beam is an easy task since only arelatively small amount of yarn would have been wound on to the beamafter the break occurred.

There will now be described with reference to the accompanying drawingsthe aforementioned embodiment, which description is by way ofillustration and not limitative of the invention.

In the drawings FIGURE 1 is a diagrammatic view of a preferredembodiment of this invention, FIGURE 2 is a diagrammatic representationof a single threadline path from a package to the beam during warping.

In FIGURE 1, is a lightweight beam pivotally mounted on a transverseshaft 22 which is rotatable about its axis and 21 is a lightweight beamspaced vertically above beam 20 and pivotally mounted on a fixed shaft23. Countor-balancing weights 24 and 25 are provided at one end of eachof beams 20 and 21 respectively. A chain 26 is suspended from the freeend of the lower beam 20, which is supported by the transverse rod 27and the other end attached to a toothed wheel 28 which is firmly mountedon shaft 22. One end of the said shaft 22 terminates in a knurledpointer knob 29 that co-operates with a fixed dial 30. The free end ofbeam 21 carries an upwardly extending fixed rod 31 having thereon aneyelet 32. An extension 33 of rod 31 extends downwardly from beam 21passing through beam 20 and terminating in a stop 34. A fixed transverseelectrical contact bar 35 is positioned between the beams 20 and 21. Athreadline 36 passing from a package to a beaming machine is led throughthe fixed eyelet 37 to the eyelet 32 mounted on rod 31 and thencethrough fixed eyelets 38 and 39.

The normal threadline tension encountered during warping is sufficientto support the beam 21, the weight of which causes the threadline 36 toflex downwardly to some extent. An increase in threadline tensionoccasioned, for example, by a fault at the creel causes the beam 21 tobe raised thus drawing the downwardly extending rod 33 through beam 20until the stop 34 meets the said beam 20. A further increase inthreadline tension to a predetermined level then causes beam 20 to beraised together with beam 21 until the former makes contact with thecontact bar 35 thus closing an electric circuit which actuates a relayand operates a stop motion to prevent further feeding of the threadlineto the warping beam. The threadline tension required to raise beam 20and thus close the electric circuit is determined by the Weight of chain26 suspended from the said beam, which weight of chain can be varied byrotating the shaft 22 by means of the knurled knob 29 and thus causingthe toothed wheel 28 to deliver or take up chain as required. The dialis calibrated in terms of threadline tension and thus the threadlinetension required to cause beam 20 to close the electric circuit can beselected by turning the knob 29 to correspond with the appropriate pointof the dial.

In this embodiment of the invention beam 21 is designed to operate as adropper arm in the normal manner. In the event of the threadline tensionfalling to zero or nearly to zero as a result of a threadline breakoccurring which may not have been preceded by an increase in threadlinetension, e.g. a creel run-out, the beam 21 falls and makes contact withcontact bar thus closing an electrical circuit and operating a stopmotion as previously described.

In FIGURE 2 a thread 101 is taken from a package 102 mounted on a creel,passed through eyelet 103 to tensioning devices 104 and thence throughmore eyelets 105 to eyelets 1116 of the stop motion actuating device 107of this invention, the foregoing all being mounted on a creel (notshown). From the stop motion actuating device the threadline is passedthrough eyelet 108 and front reed 109 of a warping machine, througheyelet 110, over a warp sheet inspection device 111, through eyelets112, back reed 113, over gumming-out bar 114 and is then wound up onbeam 115.

In operation the threadline tension at which the device is required toactuate the means for stopping the machine, hereinafter referred to asthe operating tension, is pre-set by adjusting the amount of chain 26extending between the beam 21) and the sprocket 28 by the rotation ofthe knob 29 thus determining the amount of resistance to the upwardmovement of the free end of the beam 20. The weight of the beam 20 is soarranged that rod 31 will flex the threadline downwardly between theguides under normal threadline tension so that when the tension in thethreadline increases owing to a fault occuring at the creel, forexample, the beams are raised. If the operating tension is reached beam21 makes a connection with the contact 35, and an electric circuitoperating a relay is closed, the relay in turn then actuates a means forstopping the machine. A light on the creel (not shown) indicates theposition of the faulty threadline and an operator can then takecorrective action without a break having occurred. Since the connectionbetween the beam 20 and the contact 35 may be of only a short duration,owing to snatching of the threadline for example, the relay must besensitive and must be arranged to remain closed even after the circuithas been broken again. For this purpose a silicon controlled rectifier,wired into the electrical circuit as described hereinafter, has beenfound to be effective and reliable.

In the electrical circuit a 12 volts A.C. current derived from thesecondary winding of a transformer is fed to a fullwave rectifierthrough a relay. The relay is designed to operate on a wide range ofcurrents and when energized, by the closing of a contact on the deviceof this invention, actuates a means for stopping the machine.

The output DC. voltage from the aforementioned fullwave rectifier issmoothed by a resistance and condenser and applied to a siliconcontrolled rectifier in series with a 12 volt indicating lamp with ashunt resistor. A third electrode from the silicon controlled rectifier,called the trigger electrode is connected to the electrical contacts ateach threadline position. Any contact closing at a threadline positioncauses the silicon rectifier to pass current causing the lamp to lightand the relay to operate. The silicon controlled rectifier continues topass current until a reset button is pressed after the fault whichcaused the contact to close has been removed, hence a momentary tensionsnatch is enough to cause the machine stop motion to be actuated.

In the event of a threadline breaking without the tension first risingto the operating value beam 21 falls under its own weight and makes aconnection with contact 35, the stop motion then being actuated asbefore.

Since devices of this type are frequently employed under conditions ofhigh humidity, care should be taken to ensure that their componentparts, particularly the bearings and electrical contacts, are formed ofmaterials which do not corrode under such conditions. Thus it may befound to be advantageous to form the beams and toothed wheel of a rigidplastic, metal strips being attached to the beams to provide means formaking electrical contact with the contact bar. The aforementioned metalstrips and the contact bar may be gold plated to prevent corrosion. Thebearings may conveniently be formed of polytetrafluoroethylene, whichgives a good frictionless surface under conditions of high humidity.

This embodiment may also be adapted by suitable adjustment of theoperating tension to prevent the occurrence of tight ends, that is onethreadline being wound on to the beam at a considerably higher tensionthan other threadlines, which are also known to cause difficultiesduring knitting.

What we claim is:

1. A device for actuating a stop motion device asso ciated with a threadhandling mechanism comprising: a first pivotally mounted beam movabletoward and away from a position in which said first beam actuates a stopmotion device when the tension of a thread falls below a predeterminedlimit; a second pivotally mounted beam movable toward a position inwhich said second beam actuates the stop motion when the tension of thethread rises above a predetermined limit; thread-engaging means carriedby said first beam for normally holding said first beam away from itsactuating position; means carried by said first beam and engaging saidsecond beam and moving said second beam toward its actuating positionupon a predetermined amount of movement of said first beam away from itsactuating position; and an adjustable weight carried by said second beamfor normally holding said second beam out of its actuating position.

2. A device as in claim 1 including an electrical contact bar which saidbeams engage in their actuating positions.

3. A device according to claim 1 wherein the weight acting on saidsecond beam is varied to vary the threadline tension at which that beamwill be moved to the position in which it actuates a stop motion device.

4. A device according to claim 3 wherein the weight is in the form of achain one end of which acts on the free end portion of said second beamand the other end is attached to a toothed wheel mounted on a rotatableshaft, the weight of chain acting on the beam being varied by windingportions of the chain on or off the toothed wheel by suitable rotationof the shaft.

5. A device according to claim 4 wherein the toothed Wheel and saidsecond beam are mounted on a common shaft.

6. A device according to claim 4 wherein the weight acting on saidsecond beam bears a direct relationship to the tension in the yarnrequired to cause that beam to move to the position in which it actuatesa stop motion device.

'7. In a thread-handling mechanism a device for actuating a stop motiondevice upon excessively high or excesssively low tension in thethreadline comprising: a

first beam pivotally mounted for downward and upward movement toward andaway from a lower position in which said first beam actuates a stopmotion, said first beam being urged by gravity toward said lowerposition; threadengaging means normally holding said first beam awayfrom its lower position and responsive to an excessive increase inthread tension for moving said first beam still further away from saidlower position; a second beam pivotally mounted below said first beamfor upward and downward movement between an upper position in which saidsecond beam actuates a stop motion and a lower position engaging asupport member; an adjustable weight carried by said second beam fornormally holding said second beam in engagement with said supportmember; means carried by said first beam for engaging said second beamand moving said second beam toward its upper position upon apredetermined amount of movement of said first beam away from its lowerposition, whereby excessively low tension in the threadline efiectsmovement of said first beam to its lower, actuating position and wherebyexcessively high tension in the threadline effects movement of saidsecond beam to its upper, actuating position.

8. A device is in claim 7 including an electrical contact member locatedto be engaged by said first beam in its lower position and by saidsecond beam in its upper position.

References Cited by the Examiner UNITED STATES PATENTS Re. 19,069 2/1934Wachsman 20061.l3 1,101,009 6/1914 Burke 20061.13 2,013,529 9/1935Washsman 20061.13 2,744,174 5/1956 Martin et a1. 20061.18

OTHER REFERENCES Publication: The Engineers Sketch Book of MechanicalMovements, Barber, 1918, pages 66 and 67.

BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER. Examiner.

1. A DEVICE FOR ACTUATING A STOP MOTION DEVICE ASSOCIATED WITH A THREADHANDLING MECHANISM COMPRISING: A FIRST PIVOTALLY MOUNTED BEAM MOVABLETOWARD AND AWAY FROM A POSITION IN WHICH SAID FIRST BEAM ACTUATES A STOPMOTION DEVICE WHEN THE TENSION OF A THREAD FALLS BELOW A PREDETERMINEDLIMIT; A SECOND PIVOTALLY MOUNTED BEAM MOVABLE TOWARD A POSITION INWHICH SAID SECOND BEAM ACTUATES THE STOP MOTION WHEN THE TENSION OF THETHREAD RISES ABOVE A PREDETERMINED LIMIT; THREAD-ENGAGING MEANS CARRIEDBY SAID FIRST BEAM FOR NORMALLY HOLDING SAID FIRST BEAM AWAY FROM ITSACTUATING POSITION; MEANS CARRIED BY SAID FIRST BEAM AND ENGAGING SAIDSECOND BEAM AND MOVING SAID SECOND BEAM TOWARD ITS ACTUATING POSITIONUPON A PREDETERMINED AMOUNT OF MOVEMENT OF SAID FIRST BEAM AWAY FROM ITSACTUATING POSITION; AND AN ADJUSTABLE WEIGHT CARRIED BY SAID SECOND BEAMFOR NORMALLY HOLDING SAID SECOND BEAM OUT OF ITS ACTUATING POSITION.